# BAC Calculator

> Estimate blood alcohol concentration from detailed beer, wine, spirit, and custom beverage amounts using a Widmark-style model.

Page: https://askcalculators.com/calculator/bac-calculator/
Definition: https://askcalculators.com/calculator/bac-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/bac-calculator/schema.json
Version: 2.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/bac-calculator/?unitSystem=imperial&sex=male&weightLb=180&hoursSinceFirstDrink=2&beerCount=3&beerSizeOz=12&beerAbv=5&wineCount=0&wineSizeOz=5&wineAbv=12&spiritCount=0&spiritSizeOz=1.5&spiritAbv=40&otherVolumeOz=0&otherAbv=0&metabolismRate=0.015

## Inputs
- unitSystem: Body-weight units; type=select; required; default=imperial; values=imperial|metric
- sex: Sex-based distribution factor; type=select; required; default=male; values=male|female
- weightLb: Body weight; type=number; required; default=180; min=50; max=1000; showWhen=unitSystem:imperial
- weightKg: Body weight; type=number; required; default=82; min=20; max=450; showWhen=unitSystem:metric
- hoursSinceFirstDrink: Hours since first drink; type=number; required; default=2; min=0; max=48
- beerCount: Beer servings; type=number; required; default=3; min=0; max=50
- beerSizeOz: Beer serving size; type=number; required; default=12; min=0; max=64
- beerAbv: Beer alcohol; type=percent; required; default=5; min=0; max=100
- wineCount: Wine servings; type=number; required; default=0; min=0; max=50
- wineSizeOz: Wine serving size; type=number; required; default=5; min=0; max=32
- wineAbv: Wine alcohol; type=percent; required; default=12; min=0; max=100
- spiritCount: Spirit servings; type=number; required; default=0; min=0; max=50
- spiritSizeOz: Spirit serving size; type=number; required; default=1.5; min=0; max=16
- spiritAbv: Spirit alcohol; type=percent; required; default=40; min=0; max=100
- otherVolumeOz: Other beverage total volume; type=number; required; default=0; min=0; max=1000
- otherAbv: Other beverage alcohol; type=percent; required; default=0; min=0; max=100
- metabolismRate: Assumed elimination rate; type=number; required; default=0.015; min=0.005; max=0.03

## Outputs
- estimatedBac: Estimated current BAC; format=percent; primary
- peakBac: Estimated pre-elimination BAC; format=percent
- standardDrinks: Approximate U.S. standard drinks; format=number
- alcoholGrams: Pure alcohol consumed; format=number
- hoursToZero: Additional estimated time to zero; format=number
- safetyMessage: Safety message; format=text

## Formula
Alcohol grams = volume × ABV × ethanol density; Widmark-style BAC = alcohol grams ÷ (distribution factor × body mass grams) × 100 − elimination rate × hours.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.

Notice: Never use a BAC estimate to decide whether to drive, operate equipment, supervise others, or delay emergency care. Actual BAC can be higher or lower.